Folding box construction



June 27, 1961 J. KRAMER FOLDING BOX CONSTRUCTION Filed April 16. 1954 INVENTOR. JOSEPH Kaine-e,

Wih fl w A T TOR NEYS;

United States Patent G i 2,990,098 FOLDING BOX CONSTRUCTION Joseph Kramer, Reading, Ohio, assignor, by mesne assignments, to Diamond National Corporation, a corporation of Delaware Filed Apr. 16, 1954, Ser. No. 423,760 7 Claims. (Cl. 229-32) My invention relates to folding boxes and more particularly to the so-called infolded box wherein the parts are so formed and arranged that they may be adhesively secured together while in folded condition.

An infolded box of ordinary construction, when setup or erected, exhibits a marked tendency to re-assume the folded condition due to the inherent spring of the boxboard and also the construction of the box itself. Hitherto it has been suggested that this tendency to collapse could be overcome by providing means for relatively rigidly supporting the walls of the box in set-up condition, such means forming an integral part of the box blank and functioning automatically when the box is erected to the set-up condition. For example, it has been suggested that the attachment flap at each corner of the box be provided with an extending bottom edge which will frictionally engage the bottom of the box to hold the box walls in up-right position with respect to the box bottom. Hoag Patent 2,295,515 teaches such a construction.

While the frictional engagement or drag feature of the above referred to patent has proven satisfactory from the standpoint of maintaining the body walls in erected condition, the formation of the box blanks requires a stripping operation to remove a small segment of boxboard between the attachment flaps carried by an opposite pair of the body walls and the remaining pair of body walls. Unless these narrow segments of boxboard are removed, a condition known as bunching results at the corners of the box, due to the presence of two, three, or possibly four layers of boxboard which must be folded one on the other, as well as the increased thickness of the board at the corners caused by the score lines themselves which are displaced from the plane of the blank and hence produce additional bulk particularly at the corners where the score lines come together. In

an infolded box construction wherein the attachment flaps are connected to the end edges of the end walls and the side walls are diagonally scored at their ends to provide reversely folded triangular portions to which the attachment flaps are secured, the infolding of the parts requires the end wall to be folded over the triple-thickness of the side wall, the reversely folded triangular corner portion thereof and the infolded attachment flap secured to the end wall. In addition, four score lines meet at the box corner. This causes a bunching of the material at the corner edge of the box where the parts come together which results in the mutilation of the corner, thereby weakening the structure as well as detracting from its appearance. While, as already indicated, stripping a small segment of boxboard from each corner will relieve this situation, the stripping operation is an expensive one which requires additional handling of the blanks and consequently increases their cost. It has hitherto been suggested that the condition can be relieved by providing relief openings or perforations at the juncture of the score lines defining the corners of the box bottom, but here again there is the problem of punching out the relief openings, which entails an additional handling operation.

It is, therefore, a principal object of my invention to 'provide an infolded box construction incorporating a frictional drag feature to maintain the walls in the set-up Patented June 27, 1961 condition and at the same time eliminating the necessity for a stripping or punching operation which has hitherto been found necessary to prevent bunching of the boxboard at the box corners.

This and other objects of my invention which will appear hereinafter or which will be apparent to the skilled worker in the art upon reading these specifications, I accomplish by that construction and arrangement of parts of which I shall now describe an exemplary embodiment.

Reference is now made to the accompanying drawings wherein:

FIGURE 1 is a plan view of an infolded box blank formed in accordance with my invention.

FIGURE 2 is an enlarged fragmentary plan view of a corner of my box.

FIGURE 3 is a plan view showing the blank of FIG- URE l in partially infolded condition.

FIGURE 4 is a plan view showing the blank of FIG- URE 3 in completely folded condition.

FIGURE 5 is a fragmentary perspective view of a corner of the box and is in partially erected condition.

FIGURE 6 is a partial perspective view similar to FIGURE 5 illustrating the box corner in the fully erected condition.

FIGURE 7 is a perspective view illustrating the completely erected box.

FIGURE 8 is a sectional view taken along the line 88 of FIGURE 6.

Referring now to FIGURE 1 of the drawings, I have therein illustrated a cut-and-scored blank formed from suitable material such as boxboard, which has been cut and scored to provide a main or bottom panel 1, side walls 2 and 3 articulated to opposite side edges of the main panel along parallel lines of articulation 4 and 5. End walls 6 and 7 are articulated to the remaining side edges of the main panel 1 along parallel lines of articulation 8 and 9. It will be understood that the terms side walls" and end walls are merely terms of convenience and are not intended as limitations upon my invention, since it will be apparent that the terms may be used interchangeably depending upon the dimensions of the box under consideration.

In accordance with my invention, the end wall 6 is provided at its ends with attachment flaps -10 and 11, and similarly end wall 7 is provided at its ends with attachment flaps 12 and 13. These attachment flaps are articulated to the end walls along score lines 14, 15, 16 and 17, respectively. These score lines do not, however, lie at right angles to the lines of articulation 8 and 9, but rather are inclined outwardly at an angle to the vertical somewhat greater than In addition the inner ends of the score lines contact the lines of articulation 8 and 9 at points of juncture spaced inwardly from the corners of the main panel 1. Thus, as best seen in FIGURE 2 of the drawings, the score line 14 contacts the line of articulation 8 at a point of juncture B spaced inwardly from the corner edge of the main panel, as defined by the point of juncture A of the lines of articulation 4 and 8.

In FIGURE 2, I have indicated the point B as being spaced inwardly from the corner of the main panel by a distance of approximately & which is the preferred distance where the body walls of the box are of a depth of approximately 2". This dimension is approximately equal to the Width of the lines or articulation as formed by a conventional scoring rule. -It will be understood that this dimension is exemplary only, as are the other dimensions indicated in FIGURE 2, but they will serve to establish the relation between the parts for producing a carton structure in accordance with my invention.

Thus, the inclination of the score lines 14, 1 5,, 1-6 and -17 V acterized as having their inner ends lying to the inside of the lines of articulation 4 and 5, with their outer ends lying to the outside of prolongations of the lines of articulation 4 and 5.

The attachment flaps 10, '11, 12 and 13 are separated from the side walls 2 and 3 by means of the lines of cut 18, 19, 20 and-21, respectively. These lines of cut replace the so-called hairpin cuts or removable segments generally employed to separate the attachment flaps from the adjacent walls. In accordance with my invention, the lines of cut 18, 19,20 and 21 are inclined from the perpendicular withrespect to the lines of articulation 4 and 5, the lines of cut inclining inwardly in the manner illustrated. In addition, the-inner ends of the lines of out Contact the score lines 14, 15, 16 and 17 at points of juncture spaced outwardly from the points at which. the score lines contactthe lines of articulation 8 and 9. Thus, as seen in FIGURE 2, the line of cut 18 contacts the score line 14 at a point C spaced from the point of juncture B by about or again equal to approximatelythe thickness of the score line. The inclination of the 'cutlines is such that their outer ends are spaced inwardly by approximately 95 from the prolongations of the lines of articulation 8 and 9. Thus,

as seen in FIGURE 2, the outer end of the line of cut 18 defines a point Y which is spaced inwardly from the prolongation 8a of the line of articulation 8.

Diagonal perforations 22, 23, 24, and 25 are provided in the side wall panels 2 and 3. The perforations begin at the corner edges of the main panel, i.e., at the points of intersection of the lines of articulation 4 and 5, 8 and 9, and extend outwardly at an angle of less than 45 with respect to the lines of articulation 4 and 5. Thus, in the illustrative example of FIG. 2, the line of perforation 22 is inclined at an angle of 43 with respect to the line of articulation 4. The lines of perforation serve to define triangular tabs 26, 27, 28 and 29 at the ends of the side walls 2 and 3. Instead of full lines of perforation, a combination perforation and score line may be used, the inner portions of the lines 22-25 being perforated and the outer portions scored.

In folding and gluing the blank just described, the attachment flaps 10, 11, '12 and 13 will be infolded to overlie the end walls 6 and 7 in the manner illustrated in FIGURE 3. The side walls 2 and 3 are also infolded and the triangular tabs 26, 27, 28 and 29 reversely folded to overlie the'side walls in the manner illustrated. The inclination of the score lines 14, 15, 16 and 17 and the off-set of their inner ends with respect to the lines of articulation 4 and results in the alignment of the bottom edges of the attachment flaps with the lines of articulation 8 and 9 and off-sets them inwardly from the adjacent corner edges of the side walls and the reversely folded triangular tabs. When the end walls 6 and 7 are thereafter folded to the position illustrated in FIGURE 4, this ofi-set relationship prevents bunching of the boxboard at the corners. In other words, and again referring to FIGURE 2, instead of the lines of articulation 4 and 8, the score line 14, the line of cut 18 and the line of perforation 22, all intersecting at a common point, in accordance with the prior art practice, I provide a plurality of spaced apart points of juncture at each of the corners, the points being arranged so that upon infolding of the parts, the parts will be off-set with respect to each other in such fashion that bunching of the boxboard at the corners of the box will be eliminated.

In addition to the elimination of bunching, the arrangement I have just described provides for the frictional engage'ment of the bottom edgesof the attachment flaps with the bottom or main panel of the box, thereby serving to maintain the box in the erected condition. As seen in FIGURE 5, the inclined bottom edge 18a of attachment flap 10 is arranged to frictionally engage or drag across the bottom 1 as the side walls 2 and 6 are erected to the set-up condition. It will be understood, of course, that when the end walls are infolded to the position illustrated in FIGURE 4, suitable adhesive will have been previously applied to the triangular tabs 26, 27, 28 and 29, thereby bringing about the adhesive engagement of these tabs with the attachment flaps 10, 11, 12 and 13, respectively. The inclined bottom edges of the attachment flaps, the inclination of the lines of articulation connecting the attachment flaps to the end walls, together with the angle of inclination of the lines of perforation defining the triangular tabs, cooperate in the folded and glued structure to produce the frictional contact of the attachment flaps with the box bottom in the set-up structure. The relationship of the parts in the set-up or erected condition can be best seen in FIGURES 6 and 8 of the drawings, particularly in the latter wherein the frictional engagement of the attachment flap 10 with the box bottom 1 is clearly illustrated.

Various changes and modifications may be made Without departing from the spirit of my invention and the scope of the claims which follow. I have already referred to the terms side walls and end walls as terms of convenience, and it will be understood that the attachment flaps 10, 11, 12 and 13 could be connected to the ends of the side walls, i.e., the longer pair of opposed walls with the end walls provided with the lines of perforation defining triangular tabs. The exemplary dimensions set forth in connection with FIGURE 2 are not intended as a limitation upon my invention, but rather are merely indicative of the proper relationship between the parts, and these dimensions may be altered within reasonable limits without departing from the spirit of my invention.

In addition to the aforementioned description, the box could be scored in reverse, i.e., the blank fed into the cutting press with the outer or printing surface down. Scoring in this manner would leave a welt on the outside of the box and a double ridge and valley on the inside of the box along lines of articulation 4, 5, 8 and 9. This double ridge would permit easier folding of end walls 6 and 7 since the edges of attachment flaps 10, 11, 12 and 13 would rest in the valley of the score created by this double ridge along lines of articulation 8 and 9. In addition, the same edges of these attachment flaps would rest between the score ridges along lines of articulation 4 and 5 when the box is formed, thus increasing the rigidity of the box in its set-up position.

Having, however, described my invention in an exemplary embodiment, what I desire to secure and protect by Letters Patent is:

1. In a corner construction for an infolded box, a paperboard blank cut and scored to provide a rectangular bottom panel, aside wall panel and an end wall panel articulated to adjacent side edges of said bottom panel along lines of articulation meeting at right angles to define a first point of juncture, a hinge line extending diagonally outward from said firs-t point of juncture through said side wall panel to define a generally triangular corner portion at the end of said side wall, an attachment flap hingedly connected to the end of said end wall adjacent said side wall along a score line the inner end of which contacts the line of articulation between said end wall panel and said bottom panel at a second point of juncture spaced from said first point of junction, said score line being inclined with respect to the line of articulation between said bottom panel and said end wall panel at an angle greater than so that said score line intersects a prolongation of the line of articulation between said side wall panel and said bottompanel at a point intermediate itsends, and a single line of cut, separating said attachment flap from the said triangular end portion of said side wall panel, the inner end of said out contacting said score line at a third point of juncture spaced outwardly from said second point of juncture, said line of cut defining with said score line an angle greater than 90 with the said line of cut intersecting a prolongation of the line of articulation between said end wall panel and said bottom panel intermediate its ends.

2. The structure claimed in claim 1 wherein the said first and second points of juncture are spaced apart by a distance of approximately & and wherein the second and third points of juncture are spaced apant by substantially the same distance.

3. The structure claimed in claim 2 wherein the diagonal hinge line in said side wall panel lies at an angle of less than 45 from the line of articulation between said side wall panel and said bottom panel.

4. In a generally rectangular paperboard blank for a knock-down box, a first pair of spaced apart score lines extending longitudinally of the blank in parallel relation to the opposite side edges thereof, a second pair of spaced apart score lines extending transversely of the blank in parallel relation to the end edges thereof, said pairs of score lines coming together at points of juncture A defining the corners of a bottom panel, a pair of spaced apart hinge lines at each end of the blank extending outwardly from said second score lines to the free end edges of said blank, each of said hinge lines contacting said second score lines at points of juncture B spaced inwardly from the said points A by a distance substantially no greater than the width of the said score lines, said hinge lines being inclined outwardly with respect to said second score lines at an angle slightly greater than 90, the areas between said pairs of hinge lines defining end wall panels for said structure, single lines of 6 cut extending outwardly from each of said hinge lines to the longitudinal side edges of said blank, said lines of out contacting said hinge lines at points of juncture C spaced from the adjacent points B by a distance no greater than the distance between the said points A and B, said lines of cut lying at an angle greater than with respect to the said hinge lines, the said lines of cut serving to divide the opposite sides of the blank into side wall panels lying between said lines of cut and attachment flaps at the corners of the blank, said attachment flaps being hinged to said end wall panels along the hinge lines, and lines of fold in said side wall panels extending diagonally outward from the said points A, said diagonal lines of fold defining triangular corner portions at the ends of said side wall panels.

5. The blank claimed in claim 4 wherein said hinge lines are inclined outwardly at an angle such that they will intersect prolongations of said first score lines intermediate their ends.

6. The structure claimed in claim 5 wherein said lines of cut are inclined at an angle such that they will intersect prolongations of said second score lines intermediate their ends.

7. The structure claimed in claim i6 wherein said diagonally disposed lines of fold define an angle of less than 45 with respect to said first score lines.

References Cited in the file of this patent UNITED STATES PATENTS 1,708,700 Maier Apr. 9, 1929 1,794,631 Luckett Mar. 3, 1931 1,981,187 Nuckols Nov. 20, 1934 2,295,515 Hoag Sept. 8, 1942 2,493,338 Buttery Jan. 3, 1950 

